Photoacoustic and Dielectric Study of Lead Zirconate Titanate Nanoparticles

Abstract

Using Sol-Gel method lead titanate zirconate (PZT) nanoparticles with an average size of 13.07 ± 2.8 nm, estimated from transmission electron microscopy (TEM) images, were obtained. Their X-ray powder diffraction (XRD) pattern shows a single phase of Pb(Zr _0.52 Ti _0.48 )O ₃ nanocrystallites. Photoacoustic and dielectric experiments on these PZT nanoparticles were performed in a wide temperature range; from room temperature up to 660°C. Photoacoustic experiments performed in as synthesized powders reveal an extraordinary dispersion in a large temperature interval, attributable to the size of the PZT-nanoparticles. Combining photoacoustic and dielectric results, obtained from sintered samples it was possible to establish the existence of a dispersive ferro-paraelectric transition temperature at around 470°C. Impedance curves were used to extract both frequency dependent (ϵ ′(ω)) and frequency independent (ϵ ′) dielectric constant. The temperature dependence of (ϵ ′), behaves in a quite dispersive manner, although a peak around 470°C is suggested. A much more elaborate situation is found when (ϵ ′(ω)) is plotted against temperature. At selected temperatures, frequency dependent curves of ϵ ′(ω) show that at low frequencies (< 100 Hz) there is a strong dispersion, but as the frequency increases ϵ ′(ω) tends to be frequency independent. The magnitude of ϵ ′(ω) depends slightly on the temperature.

Keywords:

• Photoacoustics
• PZT
• nanoparticles
• sol-gel

Acknowledgments

Authors wish to thank CONACYT 44318 and PAPIIT IN114006 for financial support. Authors wish also to thank Dr. J. Guzmán Mendoza for helpful discussions, and to Fis. Raúl Reyes for technical support.